With increasing age, the incidence of both bodily and behavioral dysfunction increases. The long term objective of the research proposed is to understand how aging influences the relation of physiology and performance. At present, psychophysiological changes with age are frequently attributed to alterations in general arousal. Interestingly, some authors suggest the aged are "overaroused" while others suggest that they are "underaroused". These discrepant views as well as most current work in psychophysiology raise questions about the concept of arousal. The concept continues to be widely used, however--not only in the area of aging but also in the areas of stress and performance. The current proposal directly contrasts the concept of general orousal with the concept that psychophysiological changes is largely a function of the processes employed to complete a task. Aging may change how a task is processed. These changes would then alter psychophysiological responses during the task. In short, we seek to explain psychophysiological responses better than arousal theory and thus, increase our understanding of the relation of stress, performance, and aging. Performance paradigms (divided attention and memory retrieval) are used which are known to be sensitive to aging as well as "arousal" manipulations, e.g. noise and incentive. By varying paradigms and manipulations we seek to compare the transituational validity of arousal and task requirement views. Autonomic, endocrine, motoric, and self-report dependent measures are collected. Measures of the different response systems are necessary, first, because arousal theory expects concomitant changes in all responses and second, to check for aging effects in one system altering responsivility in another. Task requirements for attentional capacity are analyzed in order to make specific predictions of the cardiovascular changes to be expected in college-aged, middle-aged, and elderly samples. We expect to show that age-related declines in the control of attention predict psychophysiological response better than general arosal theory.